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(11) | EP 0 093 806 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Compositions based on water-curable, silane modified copolymers of alkylene-alkyl acrylates |
| (57) The disclosure of this application is directed to a water-curable composition comprising
a water-curable, silane modified alkylene-alkyl acrylate copolymer, a mineral filler
and a halogenerated flame retardant additive. These compositions are useful as extrudates
about wires and cables providing insulation or jacketing thereon characterized by
resistance to deformation and by flame retardancy. |
[0001] This application relates to compositions based on a water-curable, silane modified alkylene-alkyl acrylate copolymer, mineral fillers and a halogenated flame retardant additive. The compositions of this invention are particularly useful in extrusion applications, being extruded about electrical wires and cables, and telephone wires and cables and water-cured to form crosslinked products which provide protective coatings, as insulation or jacketing, characterized by resistance to deformation and by improved flame retardant properties.
[0002] Currently, protective coatings, such as insulation and jacketing, are being applied about wires and cables by extruding thereon compositions containing an organic peroxide and subjecting the resultant articles to elevated temperatures in order to cure the compositions to crosslinked products. The overall operation, commonly referred to as peroxide curing, requires careful control of the process parameters to avoid undue heat and pressure build-up in the extruder. Undue heat and pressure build-up results in premature decomposition of the peroxide which in turn results in crosslinking of the composition in the extruder. Crosslinking of the compositions in the extruder, commonly referred to as "scorch" necessitates, in extreme cases, stopping the operation and cleaning the extruder. In situations wherein "scorch" occurs but is not as severe, it has been found that the work-life of the ultimate coatings is relatively short. In addition to the processing difficulties of peroxide curing, the peroxide containing compositions do not have that degree of resistivity to deformation, at normal peroxide loadings, demanded by many ultimate users of insulated and jacketed wire and cable articles.
[0003] The present invention provides compositions, based on water-curable, silane modified copolymers, which are characterized by improved flame retardancy and increased resistance to deformation. The compositions of this invention are particularly useful as insulation about electrical wires and cables and as jacketing about telephone wires and cables.
[0004] Furthermore, the compositions of this invention allow for wide latitude in the processing thereof in that the compositions can be extruded at temperatures far in excess of the maximum processing temperatures used in extruding peroxide containing compositions. Being capable of extrusion at higher temperatures, the compositions of the present invention can be extruded at faster rates and under lower pressures yielding protective coatings of improved surface characteristics,having improved dispersion of additives therein. ,This advantage is particularly important in heavily filled compositions such as those utilized in flame retardant applications.
[0005] In its broadest aspect, the present invention provides compositions comprising a water-curable, silane modified alkylene-alkyl acrylate copolymer, a mineral filler and a halogenated flame retardant additive wherein the mineral filler is present in an amount of from one to 100 percent by weight, preferably from 20 to 60 percent by weight; and wherein the halogenated flame retardant additive is present in an amount of from one to 100 percent by weight and preferably from 10 to 60 percent by weight.
[0006] Unless otherwise stated, percent by weight is based on the weight of the water-curable, silane modified alkylene-alkyl acrylate copolymer.
[0007] A preferred composition, for purposes of the present invention,comprises a water-curable, silane modified alkylene-alkyl acrylate copolymer, talc, as the mineral filler, and a halogenated flame retardant additive wherein the amounts are as previously defined.
[0008] Another preferred composition comprises a water-curable, silane modified alkylene-alkyl acrylate copolymer, a halogenated flame retardant additive and, as the mineral filler, an oxide, hydroxide, carbonate or sulfate of calcium or magnesium wherein the amounts are as previously defined.
[0009] Suitable water-curable. silane modified alkylene-alkyl acrylate copolymers can be produced as described in our copending application USSN No. 070,785 filed August 29, 1979, the disclosure of which is incorporated herein by reference, by reacting an alkylene-alkyl acrylate copolymer with an organo silane in the presence of an organo titanate.
[0010] The water-curable, silane modified copolymers produced contain units of Formulas I - II .described below.
[0011] Formula I - alpha olefin units having the formula:
wherein A is hydrogen or an alkyl radical having one to 16 carbon atoms, these alpha olefin units being present in the copolymers to the extent of at least 50 percent by weight;
[0012] at least 0.1 percent by weight of polymerized units containing the radical having the formula:
[0013] Formula II
wherein: B is an oxygen atom, a sulfur atom or
C1 is a carbon atom'in the main polymer chain. R is hydrogen or a monovalent hydrocarbon radical having one to 18 carbon atoms; Q is a divalent radical, such as a divalent hydrocarbon radical having 1 to 18 carbom atoms and is bonded to -B- and -D- through carbon atoms; 0 is a silicon containing radical of the formula:
wherein is hydrogen, a monovalent hydrocarbon radical of one to 18 carbon atoms or a hydrolyzable group; and Z is a hydrolyzable group; and polymerized units having the formula:
[0014] Formula III
wherein, as stated, C1 is a carbon atom in the main polymer chain and W is an alkoxy radical having one to 18 carbon atoms.
[0015] A preferred copolymer is one wherein Bis-0-, Q is -CH2-CH2-or -CH2-CH2-CH2- and Z and V are methoxy, ethoxy or butoxy and A is alkyl, exemplified by alkyl radicals for R below, or hydrogen.
[0016] Illustrative of suitable hydrocarbon radicals for R are alkyl radicals having one to 18 carbon atoms, preferably one to 4 carbon atoms such as methyl, ethyl, n-propyl, isopropyl. and n-butyl; and aryl radicals having 6 to 8 carbon atoms such as phenyl, benzyl, and xylyl.
[0017] Exemplary of suitable hydrocarbon radicals for Q are alkylene radicals having one to 18 carbon-atoms, preferably one to 6 carbon atoms such as methylene, ethylene, propylene, butylene, and hexylene; alkoxy radicals having one to 18 carbon atoms, preferably one to 6 carbon atoms such as methoxymethyl, methyloxypropyl, ethyloxyethyl, ethyloxy- propyl, propyloxypropyl, propyloxybutyl, and propyloxyhexyl; and arylene radicals such as phenylene; as well as radicals of the general formula:
wherein σ and β are integers of one to 3.
[0018] As stated, each Y can be hydrogen, a hydrocarbon radical or a hydrolyzable group. Illustrative of suitable hydrocarbon radicals are alkyl radicals having one to 18 carbon atoms, preferably one to 6 carbon atoms, such as methyl, ethyl , n-propyl, isopropyl, n-butyl, n-hexyl, and dodecyl; alkoxy radicals having one to 18 carbon atoms, preferably one to 6 carbon atoms, such as methoxy, ethoxy, propoxy, hexoxy, dodecyloxy, and methoxyethoxy; aryl radicals having 6 to 8 carbom atoms such as phenyl , methyl phenyl, and ethyl phenyl; and cycloaliphatic radicals having 5 to 8 carbon atoms such as cyclopentyl, cyclohexyl, and cyclohexyloxy.
[0019] Z, as previously stated, is a hydrolyzable group among which can be noted alkoxy radicals as previously described for Y; oxy aryl radicals such as oxyphenyl; oxyali- phatic radicals such as oxyhexyl; halogens such as chlorine, and other hydrolyzable groups as further described in U. S. -A- 3,408,420 to John B. Wiggill, patented October 29, 1968.
[0021] The alkylene-alkyl acrylate copolymers with which the organo silanes are reacted to form the silane modified copolymers are known copolymers produced by reacting an alkene with an alkyl acrylate.
[0022] Suitable alkenes are ethylene, propylene, butene-1, isobutylene, pentene-1, 2-methylbutene-1, 3-methylbutene-1, hexene, heptene-1, octene-1, vinyl chloride, and styrene, mixtures thereof.
[0023] The alkylene moiety of the alkylene-alkyl acrylate copolymer generally contains from 2 to 18 carbom atoms inclusive, preferably 2 to 3 carbon atoms inclusive.
[0024] Suitable alkyl acrylate monomers which are copolymerized with the alkenes fall within the scope of the following general formula:
[0025] Formula IV
wherein R1 is hydrogen or methyl and R2 is alkyl having one to 8 carbon atoms. Illustrative compounds encompassed by this formula are: methyl acrylate, ethyl acrylate, t-butyl acrylate, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate,and 2-ethylhexyl acrylate, and mixtures thereof.
[0026] Alkylene-alkyl acrylate copolymers generally have a density (ASTMD-1505, with a conditioning as in ASTMD-147-72) of from 0.92 to 0.94 and a melt index (ASTMD-1238 of 44 psi tested pressure) of from 0.5 to 500 decigrams per minute.
[0027] For purposes of the present invention, the preferred copolymer generally has from one to 50 percent by weight combined alkyl acrylate, preferably fran2to 20 percent by weight combined alkyl acrylate.
[0028] Suitable monomeric organo silanes reacted with the alkylene-alkyl acrylate copolymers to form the water-curable, silane modified polymers fall within the scope of Formula V below.
[0029] Formula V
wherein X is -SH,
and R3 is
or a monovalent hydrocarbon radical as defined for R, R4 is a monovalent hydrocarbon radical as defined for R and V, Q and Z are as previously defined.
[0032] Exemplary of suitable silanes falling within the scope of Formula VI are the following:
acetooxyethyltrimethoxysilane
acetooxyethyltriethoxysilane
acetooxyethyl-tris-(2-methoxyethoxy)silane
β-methacryloxyethyltrimethoxysilane
γ-methacryloxypropyltriethoxysilane_'
acetooxyethylmethyldimethoxysilane
γ -methacryloxypropyltrimethoxysilane
acetooxypropyltrimethoxysilane
acetooxypropyltriethoxysilane
γ-methacryloxypropyl-tris-(2-methoxyethoxy)silane
[0033] Other suitable silanes have the formulae:
HN2(CH2)3Si(OCH3)3
γ-aminopropyltrimethoxysilane
NH2(CH2)3Si(OC2H5)3
γ-aminopropyltriethoxysilane
HN2(CH2)2Si(OCH3)3
β -aminoethyltrimethoxysilane
HN2(CH2)2Si(OC2H5)3
β-aminoethyltriethoxysilane.
[0034] Suitable organo titanate compounds for catalyzing the reaction between an organo silane and an alkylene-alkyl acrylate copolymer can be characterized by the following formula:
[0035] Formula VII
wherein each R2, which can be the same or different, is hydrogen or a monovalent hydrocarbon radical having one to 18 carbon atoms, preferably one to 14 carbon atoms.
[0036] Exemplary of suitable hydrocarbon radicals are alkyl radicals such as methyl, ethyl, n-propyl, isopropyl, butyl, octyl, lauryl, myristyl, and stearyl; cycloaliphatic radicals such as cyclopentyl, and cyclohexyl; aryl radicals such as phenyl, methylphenyl, and chlorophenyl; and alkaryl radicals such as benzyl.
[0037] Particularly desirable titanates falling within the scope of Formula VII are those wherein each R2 is alkyl having one to 18 carbon atoms, preferably one to 14 carbon atoms, exemplified by tetrabutyl titanate, and tetraisopropyl titanate
[0038] Organo titanates falling within the scope of Formula VII are known compounds and can be conveniently prepared as described in U.S. -A- 2,984,641 to Leon E. Wolinski patented May 16, 1961.
[0039] Other suitable organo titanates are the organo titanium chelates such as tetraoctylene glycol titanium, triethanol amine titanate, titanium acetyl acetonate,and titanium lactate.
[0040] The amount of silane used can vary from 0.1 to 10, and preferably from 0.3 to 5 percent by weight based on the weight of the copalymer.
[0041] The amount of organo titanate catalyst added to the reaction mixture is a catalytic amount, sufficient to catalyze the reaction between the silane and the copolymer. A preferred amount is from 0.10 to 2.0 percent by weight, based on the weight of the copolymer.
[0042] The temperature at which this reaction is carried out is not critical and can vary, conveniently, from 80°C to 300°C and preferably from 150°C to 230°C.
[0043] The reaction can be carried out at atmospheric, subatmospheric or superatmospheric pressure, although atmospheric pressure is preferred.
[0044] Other suitable water-curable silane modified alkylene-alkyl acrylate copolymers are produced, as described incur copending application USSN No. 192,319, the disclosure of which is incorporated herein by reference, by reacting a mixture containing an organo titanate, as previously described, an alkylene-alkyl acrylate copolymer and a polysfloxane'containing repeating units of the formula:
[0045] Formula VIII
wherein R is a divalent hydrocarbon radical; each V, and Z are as previously defined; c is an integer having a value of one to 18 and x is an integer having a value of at least 2, generally 2 to 1000, preferably 5 to 25.
[0046] Illustrative of suitable hydrocarbon radicals for R3 are alkylene radicals having one to 18 carbon atoms, preferably one to 6 carbon atoms, such as methylene, ethylene, propylene, butylene, and hexylene; and alkoxy radicals having one to 18 carbon atoms, preferably one to 6 carbon atoms such as methyloxymethyl, methyloxypropyl, ethyloxyethyl, ethyloxylpropyl, propyloxypropyl, propyloxybutyl, and propyloxyhexyl.
[0047] Polysiloxanes having repeating units falling within the scope of Formula VIII can be prepared by condensing and polymerizing a silane falling within the scope of Formula V in the presence of a metal carboxylate. Among suitable metal carboxylates can be noted dibutyltin dilaurate, stannous acetate, stannous octoate, lead naphthenate, zinc octoate,and iron 2-ethyl hexoate. Conditions employed for the production of polysiloxanes, reaction temperatures, amount of materials, etc., using metal carboxylates as catalysts, are the same as subsequently described with respect to the use of organo titanates
[0048] Preferred polysiloxanes, for purposes of this invention, contain repeating units falling within the scope of Formula VIII and have combined therein an organo titanate. The organo titanate modified polysiloxanes can be used as such, to react with the copolymers of alkylene-alkyl acrylate, as explained subsequently.
[0049] The preferred polysiloxanes have a viscosity of from 0.5 poise to 150 poise, preferably from one to 20 poise as determined by a Gardner-Holt bubble viscometer at a temperature of 25°C.
[0050] At least a catalytic amount of organo titanate is used to produce the organo titanate modified polysiloxanes, that is an amount sufficient to catalyze the condensation and polymerization reaction to produce a polysiloxane. As a rule, the amount of organo titanate used in on the order of from 0.001 to about 25 percent by weight based on the weight of the monomeric silane. It is preferred to use from 0.5 to 5 percent by weight of organo titanate based on the weight of the monomeric silane.
[0051] The temperature at which the reaction is conducted can be varied over a wide range, for example from 0 C to 250°C. A temperature in the range of from 70 C to 130°C is preferred. Also the reaction can be conducted using a suitable solvent, illustrated by hydrocarbon solvents such as toluene, xylene, cumene, decalin, dodecane, and chlorobenzene.
[0052] The reaction between the organo titanate and the monomeric silane can be conducted under atmospheric, subatmospheric or superatmospheric pressure. It is preferred to conduct the later stages of the reaction under subatmospheric pressure to allow for more facile removal of volatile by-products. Also, the reaction is preferably conducted under the atmosphere of an inert gas such as nitrogen or argon to avoid formation of a gel due to the water sensitivity of the product.
[0053] Completion of the reaction is evidenced by cessation of the evolution of volatiles and the weight/volume of volatiles collected as compared to the theoretical weight/volume. Alternatively, the reaction can be run to a desired viscosity level and the reactants cooled to stop the reaction.
[0054] The production of a silane modified copolymer of an alkylene-alkyl acrylate is carried out by reacting a polysiloxane, as described with a copolymer of an alkylene-alkyl acrylate in the presence of an organo titanate catalyst.
[0055] In those instances wherein the polysiloxane contains combined organo titanate, additional organo titanate catalyst may not be necessary, especially when at least about 0.5 percent by weight organo titanate, based on the weight of the monomeric silane, was used in the preparation of the polysiloxane.
[0056] The amount of organo titanate catalyst added to the reaction mixture is a catalytic amount, sufficient to catalyze the reaction between the polysiloxane and the copolymer. A preferred amount is from 0.001 to 50 percent by weight, most preferably from 0.1 to 25 percent by weight based on the weight of the polysiloxane.
[0057] The amount of polysiloxane used can vary from 0.05 to 10, and preferably from 0.3 to 5 percent by weight based on the weight of the copolymer.
[0058] The temperature at which this reaction is carried out is not critical and can vary, conveniently, from 80 C to 300°C and preferably from 150°C to 230°C.
[0059] The reaction can be carried out at atmospheric, subatmospheric or superatmospheric pressure, although atmospheric pressure is preferred and in the presence of solvents as previously described.
[0061] Recovery of the silane modified copolymer is effected by allowing the contents of the reaction flask to cool and discharging to a suitable receiver for storage preferably under an inert gas blanket.
[0062] The reaction can be carried out in any suitable apparatus, preferably an apparatus in which the copolymer is subjected to mechanical working such as a Brabender mixer, a Banbury mixer or an extruder. The polysiloxane can be added to the fluxed copolymer and the organo titanate, if needed, then added. Alternatively, the organo titanate, if needed,can be added to the copolymer prior to the addition of the polysiloxane. Also, organo titanate and polysiloxane can be premixed and added 'to the fluxed polymer.
[0063] Other suitable water-curable silane modified alkylene-alkyl acrylate copolymers can be produced by grafting an unsaturated silane such as vinyl trimethoxysilane, vinyl tri- ethoxy silane, β-methacryloxyethyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane onto an alkylene-alkyl acrylate copolymer as described in U.S. -A- 3,646,155 patented February 29, 1972, the disclosure of which is incorporated herein by reference.
[0064] As previously stated the compositions of this invention comprise a water-curable, silane modified alkylene-alkyl acrylate copolymer, a mineral filler and a halogenated flame retardant additive.
[0065] Illustrative of suitable mineral fillers are the following: talc, aluminum trihydrate, antimony oxide, barium sulfate, calcium silicate, molybdenum oxide, silica, red phosphorus, zinc borate.clay,and calcυm or magnesium salts or bases as previously described. As indicated, the preferred mineral fillers are talc, calcium or magnesium compounds per se or coated with a metal salt of a fatty acid having 8 to 20 carbon atoms wherein the metal is of Groups Ia, IIa or IIb of the Mendeleev Periodic Table of Elements. Acids used to form the metal salts are saturated or unsaturated monobasic or dibasic, branched or straight chain fatty acids of 8 to 20 carbon atoms. Exemplary of such acids are palmitic, stearic, lauric, oleic, sebacic, ricinoleic, and palmitoleic; with stearic acid being preferred. The preferred metal salts are calcium stearate and zinc stearate.
[0066] The preferred mineral fillers can also be coated with a compatible hydrophobic material such as an organo silane, an organo titanate or a metal salt of a fatty acid, previously described.
[0067] Mineral fillers can be conveniently coated using from 0.05 to 5 parts by weight of hydrophobic material per 100 parts by weight of mineral filler, in a manner as described in U.S. -A- 4,255,303 granted March 10, 1981.
[0068] Halogenated flame retardant additives which are used in the formulation of compositions of this invention are well known to those skilled in the art. These flame retardant additives are halogenated (brominated, chlorinated or fluorinated) organic compounds. The preferred halogenated organic compounds include chlorinated polyethylene, polyvinyl chloride, polyvinylidene chloride, polyvinyl chloride copolymers, halogenated paraffin and paraffin waxes, chlorinated alicyclic hydrocarbons, and brominated aromatic compounds. The most preferred include decabromodiphenyl oxide and compounds of the following general formulae:
and
wherein R is independently chlorine or bromine and m is an integer from one to 6, such as ethylene bis(tetrabromophthalimide).
[0069] In addition to the water-curable, silane modified alkylene-alkyl acrylate copolymer, mineral filler and flame retardant additive, the compositions of thisinvention can contain additives such as carbon black, lubricants, UV stabilizers, dyes colorants, antioxidants, and smoke inhibitors.
[0070] It is to be understood that mixtures of mineral fillers, flame retardant additives, silane modified alkylene-alkyl acrylate copolymers and additives can be used if so desired.
[0071] The compositions of the present invention are conveniently formulated by blending in a suitable apparatus such as a Brabender mixer as described in the Examples which follow.
[0072] Curing of the compositions to crosslinked products is carried out by exposing the compositions to moisture. The moisture present in the atmosphere is usually sufficient to permit curing to occur over a period of 48 hours.
[0073] The rate of curing, in a matter of 30 minutes, can be accelerated by exposure to an artificially humidified atmosphere or immersion in water, and heating to elevated temperatures or by exposure to steam. Generally, curing is effected at temperatures of the order of from 23°C to 100°C, preferably from 70°C to 100°C.
[0074] Additionally, curing may be accelerated by the use of a silanol condensation catalyst such as dibutyltin dilaurate or an organo titanate.
[0075] Compositions of the present invention, Examples 1-7, the formulations of which are described in Table 1, were prepared as follows:
[0076] All ingredients with the exception of the organo titanate, the monomeric silane, the polysiloxane and the dibutyltin dilaurate were mixed to homogeniety in a Brabender mixer which had been preheated to a temperature of 160°C. After homogeniety was attained, the organo titanate, the dibutyltin dilaurate and the monomeric silane or polysiloxane were introduced into the Brabender mixer. The mixture was reacted for 30 minutes at a temperature of 160°C - 170°C and the resultant composition containing the water-curable, silane modified alkylene-alkyl acrylate copolymer was discharged hot into a polyethylene bag and kept under a blanket of argon.
[0077] Samples of each composition were used to prepare test plaques, having dimensions of 3 inches by 8 inches by 0.125 inch in a'press, under the following conditions:
Pressure 5000. psi
Temperature 130°C
Time Cycle 5 minutes
[0078] Controls 1-4, peroxide based.compositions, the formulations of which are described in Table 1, were prepared by admixing the components in a 40 gram Brabender mixer, which had been preheated to a temperature of 120°C for about 5 minutes. After the 5 minute period, the contents of the Brabender were discharged hot, flattened in a press and allowed to cool.
[0079] Samples of each composition were used to prepare test plaques, having dimensions of 3 inches by 8 inches by 0.125 inch, in a press under the following conditions:
Pressure 5000 psi
Temperature 180°C
Time Cycle 15 minutes
[0080] Plaques of compositions 1-7 and controls 1-4 were then subjected to the following tests:
Limiting Oxygen Index---ASTMD-2863-70
Monsanto Rheometer Cure-Described in Detail U.S. Patent 4,018,852 granted April 19, 1977
Decalin Extractables----ASTMD-2765
Deformation-------------ASTMD-621
[0081] As to these tests, a higher Rheometer value indicates that the product has cured to a higher crosslinked density; a higher value for Limiting Oxygen Index indicates better flame retardant properties; a lower value for Decalin Extractables indicates a higher degree of crosslinking; a lower value for Deformation indicates improved resistivity to deformation. The values reported are averages obtained on testing two plaques in each instance.
[0083] The decabromodiphenyl oxide noted in the examples contained 83 percent by weight combined bromine.
[0084] The polysiloxane noted in the examples had a viscosity of 3.4 poise and a repeating unit of
wherein x=8-9
EXAMPLE 8:
[0085] A composition was extruded onto a 114 AWG solid copper wire by feeding a composition, described in Example 6, with the exception of the polysiloxane, the tetraisopropyl titanate and the dibutyltin dilaurate, into a 2½, 24 to 1 (length to diameter) Royle Extruder,combining in the extruder, the initial feed with a second feed of a mixture of the polysiloxane, the tetraisopropyl titanate and the dibutyltin dilaurate. The amount of the second feed was 1.4 percent by weight based on the weight of the first feed. The weight ratio of polysiloxane to tetraisopropyl titanate to dibutyltin dilaurate was 24 to 4 to 1. The resultant reacted composition was extruded onto the wire under ,the following conditions:
The coated wire was fed through a water trough, which was at ambient temperatures, with the result that the composition on the wire was cured to a crosslinked product having a thickness of about 30 mils.
[0086] Tests were conducted on the coated wire as well as on plaques formed from material stripped from the wire. The stripped material was deformed into plaques, having dimensions of 3 inches by 8 inches by 0.125 inch, in a press under the following conditions:
Pressure 5000 psi
Temperature 150°C
Time Cycle 15 minutes
Monsanto Rheometer cure - 35.5 inch-pound (average value of 3 plaques)
Tensile Elongation - 1700 psi (average value of 3 plaques)
Deformation - 25.9 percent (average value of 3 plaques) Union Carbide Corporation Standard Testing Method WC-75-A at 121°C
Deformation on Wire -18.5 percent Union Carbide Corporation Standard Testing Method WC-75-B at 121°C
Composition passed the VW1 flame test indicating good flame resistance. Underwriters Laboratories Testing Method in UL Subject 44 (Revised 1974 Edition).
With respect to extruding the compositions of this invention onto a wire and cable the temperatures used, broadly speaking, range from 100 to 300°C, preferably 150° to 230°C.
[0087] The compositions of this invention have been described principally for use in extrusion operation for application to wire and cable coating. It is to be understood that these compositions are also useful for extruded pipe, foamed articles, blow molded articles, injection molded articles, heat shrinkable articles, as well as, for application with fiberglass, graphite fibers, nylon fibers and the like for extruded sheet.
1. A water-curable composition comprising a water-curable, silane modified alkylene-alkyl
acrylate copolymer, a mineral filler and a halogenated flame retardant additive, wherein
the mineral filler is present in an amount of from one to 100 percent by weight based
on the weight of the copolymer and the halogenated flame retardant additive is present
in an amount of from one to 100 percent by weight based on the weight of said copolymer.
2. A water-curable composition as claimed in claim 1 wherein the mineral filler is
present in an amount of from 20 to 60 percent by weight, and wherein the halogenated
flame retardant additive is present in an amount of from 10 to 60 percent by weight.
3. A water-curable composition as claimed in claim 1 or claim 2 wherein the mineral
filler is an oxide, hydroxide, carbonate or sulfate of magnesium or calcium, antimony
oxide or trioxide, or talc, or a mixture thereof.
4. A water-curable composition as claimed in claim 3 wherein the mineral filler is
coated with a compatible hydrophobic material.
5. A water-curable composition as claimed in claim 4 wherein the hydrophobic material
is a metal salt of a fatty acid.
6. A water-curable composition as claimed in claim 5 wherein the metal salt of a fatty
acid is calcium stearate or zinc stearate.
7. A water-curable composition as claimed in any one of the preceding claims wherein
the alkylene-alkyl acrylate copolymer is an ethylene-ethyl acrylate copolymer.
8. A water-curable composition as claimed in any one of claims 1 to 6 wherein the
alkylene-alkyl acrylate copolymer is an ethylene-ethyl acrylate- t-butyl acrylate
copolymer.
9. A water-curable composition as claimed in any one of the preceding claims wherein
the silane is derived from acetooxyethyltrimethoxysilane.
10. A water-curable composition as claimed in any one of the preceding claims wherein
the halogenated flame retardant additive is decabromodiphenyloxide.
11. A water-curable composition as claimed in any one of claims 1 to 9 wherein the
halogenated flame retardant additive is ethylene bis-(tetrabromophthalimide).
12. A water-curable composition as claimed in any one of claims 1 to 9 wherein the
halogenated flame retardant additive is an aromatic bromine compound.
13. The crosslinked product of a composition as claimed in any one of the preceding
claims.
14. A wire or cable having as a coating thereon a composition or a crosslinked product
as claimed in any one of the preceding claims.
15. A molded article produced from a composition or crosslinked product as claimed
in any one of the preceding claims. MGB/SJW/DR/EA599